The technique disclosed herein relates to data storage equipment and method of controlling it and, more particularly, to data storage equipment used in a remote copy environment in a computer system having a plurality of computers and a plurality of data storage units and to a method of controlling the data storage equipment.
As the amount of data has increased explosively, the number of host computers within a computer system and the capacities of storage systems tend to increase. Furthermore, in order to process a huge amount of data, plural host computers are often run in cooperation. One example of this is a computer system in which the results of processing performed by one host computer are input to and processed by another host computer.
Additionally, as businesses depend more on information processing systems and the amount of damage caused by lost of data increases to an enormous level, the importance of disaster recovery of the data increases.
Where duplication for disaster recovery of a computer system is carried out by the prior art technique, each host computer has instructed a storage system under control of the host computer itself to copy data for the host computer itself. The copy made by the storage system is controlled by the host computer that specifies the corresponding storage area of a copy-source storage system and the corresponding storage area of a copy-destination storage system.
In the technique disclosed in US2005/0154829A1, one host computer of a computer system performs a batch copy into arbitrary or whole storage area within data storage equipment in the computer system including plural host computers and a storage system. Specified ones of storage areas offered by the disk equipment are collectively defined as a group. A copy can be performed by specifying such a group. Each group is made up of an assemblage of subgroups. Subgroups are defined for each computer. The consistency of the order of copy operations among the computers is assured.
US2005/0114467A1 discloses a technique for gaining the status information about remote copy of a storage subsystem in a remote location by a host computer, the subsystem being not directly coupled to the host computer.
Where a primary storage system for storing data to be written (hereinafter may be referred to as “write data”) from a host computer is different among different host computers, a certain one host computer has not collected the status of the primary storage area possessed by each primary storage system or the status of a pair formed by a secondary storage area of a secondary storage system and a primary storage area. Therefore, the status of the whole computer system has not been managed efficiently.